B9 Revision Flashcards
What is homeostasis?
The process of maintaining a constant body temperature.
Three layers of skin
Epidermis, Dermis, Fatty Tissue
Parts of the Epidermis
Skin Cells and fine Hairs
Where does hair grow out of?
Hair follicles
What is the pouch inside a hair follicle?
Sebaceous gland
What is the function of the Sebaceous gland?
To produce oil
What joins the hair follicle to the skin?
Hair erector muscle
What happens when you are cold?
The hair erector muscle contracts, pulling the hair upright which allows for air to be caught between the hair which creates a layer of warmth around your skin.
What happens when you are hot?
The hair erector muscles relax, causing the hairs to lie flat, so no air gets trapped and no warmth.
What do the sweat glands look like?
Like a messy ball of string
What happens to the sweat glands when you are hot?
They release sweat onto the surface of the skin via a sweat pore, the sweat then takes heat away from the body as it evaporates.
What do the arterioles do?
Provide blood to the structure of the Dermis.
What happens to the arterioles when the body is hot?
They become wider, is a process called vasodilation. Allowing for blood to flow closer to the surface of the skin and radiate out heat.
What is the purpose of the pressure receptors?
To detect when you touch something
What changes the activity of one or more specific target organs, is carried by the blood, produced by glands, and is a chemical substance?
Hormones
What system that coordinates the body’s response to changes in the environment using hormones
endocrine system
What are groups of cells that produce hormones and secrete them into the bloodstream where they travel to target organs.
endocrine glands
What hormone do the Testes produce and what does it do?
Testosterone, controls puberty and sperm production.
What hormone do the Ovaries produce and what does it do?
Estrogen, controls puberty and a main hormone in controlling the menstrual cycle
What hormone do the adrenal glands produce and what does it do?
Adrenaline, triggers the flight or fight response when there is danger.
What hormone doe the Pancreas produce?
Insulin and Glucagon
What does Insulin do?
Acts to decrease blood glucose levels
What does glucagon do?
Acts to increase blood glucose levels
What is a negative effect of a too high blood glucose level?
Can have negative impact on osmosis
What is a negative effect of a too little blood glucose level?
Can’t produce enough energy
What organ can detect if the blood glucose concentration is too high or too little?
The pancreas
What is released by the pancreas if the concentration of blood glucose is too high?
Insulin
What is released by the pancreas if the concentration of blood glucose is too low?
Glucagon
What detects the presence of insulin?
Liver and muscle tissues
What do the liver and muscle tissues do when they detect insulin?
They convert excess glucose into glycogen.
What detects the presence of Glucagon?
The liver
What does the liver do when it detects glucagon?
It converts stores of glycogen into glucose to be released into the bloodstream.
What is a form of glucose that is insoluble and can be stored for later use?
Glycogen
What structure of the eye refracts light?
Cornea
What structure of the eye controls how much light enters the pupil?
Iris
What structure of the eye focuses light onto the retina?
Lens
What structure of the eye contains the light receptors?
Retina
What structure of the eye carries impulses between the eye and the brain?
Optic nerve
What is it called when the size of the pupil changes in response to bright or dim light?
The pupil reflex
How does the eye react to dim light?
Radial muscles of iris contract, circular muscles of iris relax, so the pupil is dilated and more light enters.
How does the eye react to bright light?
Radial muscles of iris relax, circular muscles of iris contract, so the pupil is contracted and less light enters
What is the ability of the lens to change its shape called?
Accommodation
When an object is near the ciliary muscles _____ and the suspensory ligaments become ______
Contract, Slackened
When an object is far the ciliary muscles _____ and the suspensory ligaments become ______
Relax, Stretched
What detects stimuli?
Receptors
What receives and processes information from receptors around the body?
The coordination center
What are examples of the coordination center?
Brain, spinal cord, and pancreas.
What brings about responses, restoring optimum levels like core body temperatures and blood glucose levels?
Effectors
Muscles and glands are a type of what, which can bring about muscle contraction or hormone release?
Effector
What are nerve cells called?
Neurones
What is the function of the Neurons?
Carry electrical signals from one place to another
What is a bundle of neurons called?
A nerve
What are the three main types of neuron?
Sensory, motor, relay.
What is the path of the reflex arc?
Stimulus → receptor → coordinator → effector → response
What neuron detects a stimuli?
Sensory Neuron
What neuron receives electrical impulses from sensory neurons and sends them to motor neurons?
Relay Neuron
What sends electrical impulses to an effector?
Motor Neuron
What are the parts of the central nervous system?
The brain and the spinal cord
What are the parts of the peripheral nervous system?
Anything other than brain and spinal cord.
